Ion exchange materials and method of



Sept. 6, 1960 w. JUDA ErAL I Re 24,865

ION EXCHANGE MATERIALS AND METHOD 0F MAKING AND USING THE SAME OriginalFiled July 9, 1949 Ohms (x /0) ways.

United States Patent ION EXCHANGE MATERIALS AND METHOD OF MAKING ANDUSING THE SAME Walter Juda and Wayne A. McRae, Lexington, Mass.,

assignors, by mesue assignments, to Iouics Incorporated, Cambridge,Mass., a corporation of Massachuseits Original No. 2,636,851, dated Apr.28, 1953, Ser. No. 103,784, .luly 9, 1949. Application for reissue Sept.3, 1959, Ser. No. 824,146

72 Claims. (Cl. 204-98) Matter enclosed in heavy brackets fl appears `inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

KCl solution, of less than 1.5 X10-1 ohm-1 per cm. This potential isdetermined at 25 C. in the system: 35 caloruel saturated 0.1 M membrane0.01 M saturated electrode KCl KCl KO1 KG1 solution solution solutionsolution diffusion diiusion protected. protected The poor conductivityof such membranes necessitates the use of thin and structurally weakmembranes of not more than .030 to .050 mm. thickness, in order toeffect the transfer of ions therethrough.

These collodiou membranes have been examined and tested, and both typesof such membranes exhibit only very weak base exchange and anionexchange properties, respectively. Moreover, even the most effective ofthese membranes have low total acid numbers ranging from l to 3.3 (astitrated in a solution of the prepared collodion in an organic solventwith alcoholic potassium hydroxide) corresponding to 0.01 'to 0.033milliequivalent of acid per gram of dry collodion. Of this amount oftotal acid, only a fraction of one per cent is available for baseexchange. This large discrepancy between the total acid and exchangecapacity accounts for the very weakly acid character of collodionmembranes, which is due to the preponderance of acid groups having verylow dissociation constants. Similarly, the protamine type of impregnatedelectropositive collodion membranes are only weakly basic.

Ion-exchange materials have been made of organic resins, but these havebeen produced solely in the conventional form of beads or granules ofsmall particle size, averaging usually considerably below 1/s indiameter, or in respect of the largest dimension of each particle. Thesesmall granular exchangers have been and could therefore only be used insystems in which they were either contacted with the solution untilequilibrium was reached or the solution was percolated through astationary bed of the exchanger granules. In this case, ion exchangenecessarily consisted merely of the transfer of ions from the solutiontonto the resin and from the resin back Reissued Sept. 6, 1960 "ice yinto the same solution. Hence, in order to exchange ions between twodifferent solutions, it was necessary to first exhaust the capacity ofthe exchanger by means of a first solution and then regenerate theexchanger by contacting it with a second solution. This method ofoperating cation exchangers has the disadvantage of being non-continuousand uneconomical in that it requires substantial exhaustion oftheexchange materials in each half of the cycle.

It is an object of this invention to provide ion-exchange materials, inthe form of coherent, uniform, permselective structures of increasedelectrical conductivities, of substantial ion exchange capacities and ofstrongly acid and/or strongly basic and/or substantially dissociatedsalt characteristics. lt is a further object to prepare suchion-exchange materials, in an integral, uniform solid, unfracturedstructure and with substantial crosssectional dimensions orareas-greater, f-or example, than those of beads or granules-and atleast one quarter inch or more in at least one dimension. It is also anobject of the invention to provide `a method of preparing suchpermselective coherent structures and of applying the same to the usefularts. Other objects of the invention will appear from the followingdisclosure.

It is found by the present invention that ion-exchange materials may bemade which are not only more effective in their function of effectingion-exchange but which may also acquire the novel additional function ofeffecting, both ion-exchange and ion-regeneration, progressively andsimultaneously-and hence, continuously--so long as a difference of ioncharacteristics or ion concentration is maintained across or through theion-exchange mate rial or medium.

A criterion for these additional functions is that the calomel electrodeion-exchange material shall be comprised in a coherent and relativelyuniform structure, containing water in an amount at least 15% by weightof the dry exchange material, and also contain (or consist of) inintegrated association therewith, an ion-exchange component which issubstantially insoluble in water but which is freely dissociabletherein, the ion-exchange component being oriented with respect to itsdissociable ions so as to present a predominant proportion or amount ofthe same in the exposed surfaces of the structure o-r interface betweenthe ion-exchange material and the aqueous-filled voids. The ion-exchangecomponent is preferably substantially water insoluble and characterizedby having one of its ions, upon dissociation, remain integral with andfixed to the coherent polymeric matrix of the ion-exchange material,while the other ion, upon dissociation, is released as a mobile, activeion, into the aqueous filled voids of the ion-exchange material ormedium. That is to say, in general the structures of this inventioncomprise, as an essential part extending substantially throughout, apredominant arnount of an ion-exchange resin which resin may be definedas an insoluble, infusible, synthetic organic polymeric matrix havingdissociable ionic groups chemically bonded thereto and having water ingel relationship therewith. An important feature of the structures ofthis invention is the presence of the gel water in an amount of at least15% of the weight of the dry ionexchange resin, whereby this structureis rendered highly conductive electrically.

The membrane or diaphragm which is thus formed by the ion-exchangematerial or medium of the present invention is therefore typically of acoherent, uniform, conductive permselective structure, such as acontinuous gel,

in contrast to impermeable or non-conductive films or membranes ornon-uniform, gelatinous precipitates or granular exchange materials ofthe prior art.

The permselective structure of the present invention may comprise or becomposed of a binder material, with which the ion-exchange material isintegrally associated, the ionic groups of the ion-exchange materialbeing in oriented, dissociable relation with respect thereto and to theaqueous phase of the structure. The permselectve struc-ture of theinvention may be composed of polymerized organic segments which arechemically combined with each other to constitute a coherent uniformstructure, but which are also chemically combined with and form a partof the molecules of the ion-exchange component, per se. Moreparticularly, the polymerized component is combined with the xed ion ofthe ion-exchange component, which is oriented with respect to thepolymerized component so as to be predominantly in the outer surface ofthe structure. Upon dissociation of the ion-exchange component, thefixed ion remains in the solid exposed surface of the structure, whilethe other ion becomes a mobile active ion, liberated in the aqueousfilled voids.

A representative and preferred procedure for the preparation of suchion-exchange diaphragms of the present invention is to dissolve `ordisperse appropriate polymerizable organic compounds, in water, and thento effect polymerization, and especially curing to the water-insolublestage, and preferably to the final stage of curing which is to beeffected, of the thus dispersed reagents, in the aqueous medium as byheat, pressure, `and the like (without segregation `or evaporation),whereupon the resulting polymer is constrained to cure to 1an integratedgel formation, throughout the dispersion, thereby to constitute acoherent structure, membrane or diaphragm of `a shape and dimensionscorresponding to those of the dispersion in which such curing takesplace.

In such dispersion, polymerization and curing-if the polymerizingreagent materials possess or form a dissociable component-it is foundthat the aqueous dispersion effects and maintains the orientation ofsuch component outwardly from the polymerizing and curing componentstoward and into the aqueous or dispersing phase, and that thepolymerizing components tend t-o aggregate into and form a homogeneouscontinuous, solid, and ultimately coherent phase, occluding the aqueousphase.

Moreover by maintaining the liquid aqueous dispersing phase present andeiective throughout the polymerization-without evaporation and withoutsegregationthe cured polymer acquires and retains a gelstructurecharacterized by an extensive interface between the curedpolymeric structure and the gel water-in the interfaces of which thedispersed, oriented, dissociable components are concentrated, andmaintained subject to dissociation into a fixed ion therein, and amobile active ion, which is free to migrate into and throughout theaqueous phase or gel Water.

It is found that in order to effect and preserve these relationships andthe free permeability of the solidified gel structure, throughout, theaqueous medium should form at least 15%, by Weight, of the weight of thedry ion-exchange component, and should not at any time be allowed tobecome less, as by dry-ing, etc., lest the continuous coherent structureof the whole should be disrupted or its exposed electric or surfacecharacteristics and ion-exchange function be interfered with ordestroyed.

The formation of organic polymers under the usual conditions of curing,of the prior art-wherein media are used other than water, or from whichwater, if present, is allowed to segregate or escape-does not permitorientation of the components or result in a continuous permselectivestructure, but in one which is subject to rm impervious solidication andeven fracture (non-aqueous resinous beads) upon shrinkage, or otherwise.Either a continuous ion-impermeable structure or a fractured structurewould be unsuitable for thet purpose of the present invention. l

By the present procedure, the ion-exchange resin, Whether it constitutesa chemical component of the polymerized structure, or is physicallyassociated therewith, is incorporated integrally and simultaneously withthe initial curing of the structure with its dissociable componentdirected to and into the aqueous phase of the dispersion and of theresulting gel.

It has now been found, for example, that solid, physically stablestructures, including membranes, diaphragms, sheets, rods, tubes,vessels and objects of many different shapes (having at least one andmore particularly at least two dimensions greater than MW) can beprepared presenting Water-insoluble, coherent, ion-exchange materials ofhigh specic conductivities. According to this invention suchion-exchange materials are of high specic conductivities, exceeding .5102 ohm1 cm.1 and of high capacities, and contain substantial amounts ofdispersed Water, not less than 15% of the weight of lthe air dryexchanger material and up to such proportions as might mechanicallyinterfere with its uniform, coherent or permselective characteristics.

Such coherent structures may generally be made by casting, molding(including compression molding, if without substantial loss orsegregation of the water component) and other conventional means ofproviding large continuous coherent structures of thermosetting orthermoplastic resins, except that the structures of this invention aremade and maintained in aqueous media and/or an atmosphere ofsubstantially saturated humidity, so as to prevent evaporation. In thismanner the active groups attached to the polymeric organic matrix andoriented with respect to the interfaces thereof are partially orcornpletely dissociable in the internal gel Water into fixed ions of onesign linked to the polymer and into mobile ions of opposite sign. Thelatter are exchangeable ions and the main or substantially sole carriersof electric current.

In order to obtain the above high conductivities with active groups ofrelatively low dissociation constants between 105 and 10-3, whenmeasured in the form of one resin-forming ingredient in aqueous solutionprior to condensation or polymerization, it is necessary to provide ahigh density of such groups, that is, unusually high exchangecapacities, exceeding 3 milliequivalents (m. eq./ gram) per gram of dryexchanger. 0n the other hand, in the case of ion-exchangers having thepreferred strongly dissociated active groups (i.e. having a dissociationconstant above 10x-3) smaller exchange capacities, of not less than 0.3milliequivalent per gram of dry exchanger have now been found to beentirely adequate to give the above conductivities'.

It has further been found that the preferred coherent resinous materialscontaining at least 15% of internal gel Water and having an exchangecapacity exceeding 0.3 milliequivalent per gram of dry exchanger, saidcapacity being substantially due to active acid and/or basic and/or saltgroups having a dissociation constant greater than l0-3 undergoelectrolysis when subjected to direct currents in a sutliciently strongelectric field, as evidenced by the appearance of electrolysis productsat the electrodes. To give a simplified picture of this novel type ofelectrolysis, it is believed that the mobile ions carry the primaryportion of the current and that they are presumably discharged at theelectrode, whereas the fixed ions of opposite sign presumably decomposesome of the gel water thereby producing an equivalent amount ofsecondary mobile ions which discharge on the other electrode. Thesepreferred materials capable of undergoing electrolysis may therefore bedesignated as solid, coherent synthetic resinous permselectiveion-exchange electrolytes, of strongly acid or strongly basic orsubstantially dissociated salt character.

ySuitable active acidic functional groups linked to a` polymeric matrixinclude -SO3H, -COOH and the like,

SQ-,H being preferred because of its high dissociation cons-tantexceeding l0*3 in suitable resin-forming compounds. The exchangeablehydrogen ion may be partially or completely substituted by othersubstantially dissociated cations such as the alkali metal ions, thealkaline earth metal ions--namely, calcium, strontium, barium andradium-and also silver, copper, magnesium and ammonium ions, and thelike. Typical polymeric matrices to which the functional groups arelinked include phenolaldehyde resins; polystyrene-divinylbenzenecopolymers and the like. Similarly suitable active basic groups linkedto polymerio matrices include quaternary ammonium hydroxides- R1 RzN-OHamino groups, the guanidyl group,

HN=C

the dicyandiamidine group and the like organic nitrogen containing basicgroups.

Quaternary ammonium hydroxide groups, the guanidine and thedicyandiamidine residue are among the preferred basic groups because oftheir high dissociation constant exceeding lU-3. Typical polymers towhich active basic groups are linked include the urea-formaldehyde typeresins, the melamine-formaldehyde type resins, the polyalkylenepolyamine formaldehyde resins and the like. The exchangeable hydroxylions may be partially or completely substituted by other substantiallydissociated anions such as Cl, NO3, S04- and the like.

The permselective character of the coherent ion-exchange structure ofthis invention, and more particularly of the coherent ion-exchangeelectrolytes is shown by the observation that they have either acharacteristic concentration potential of the order of 55 millivoltswhen measured in a concentration cell by means of the calomel electrodesystem previously described, or an appropriately modified concentrationpotential measured by means of a different thermodynamic system, such assilver-silver chloride electrodes immersed in two different solutionswithout salt bridge. It has further been discovered that their highconductivities and their physical stability make possible a greatvariety of novel applications in which diaphragms comprising coherention-exchange electrolytes are used as a barrier to separate two or moresolutions of electrolytes, for example, for the purpose of transferringions of one sign at the substantial exclusion of ions of the oppositesign. Such systems comprising ion-exchange electrolyte diaphragmsseparating at least two solutions of electrolytes may either be used assuch in a variety of applications relying primarily on theirion-exchange properties or they may be used in electrolytic cells. Moreparticularly we prepare and ,use solid diaphragms comprising solidionexchange electrolytes and we separate by means of these diaphragmeand ion-permeable membranes two solutions containing either at least twodifferent concentrations of the same species of ions; or at least twodiiferent species of ions, thereby effecting exchange of ions of onecharge between two solutions at the substantial exclusion of exchange ofions of the opposite charge, and/or exchange of small ions with thesubstantial exclusion of exchange of large ions. We may enhance theeifectiveness and the rates of such exclusive exchanges by applyingelectric fields across the two solutions separated by ion-exchangediaphragms.

Further, we use coherent ion-exchange diaphragms of high conductivityand permselective membranes in the construction of primary and secondary(storage) electromotive force cells in which the diaphragm or membrane.

separates two solutions of different electrochemical potential.

Representative examples of the specific preparation and applications ofthe ion exchange medium or materials, in accordance with the invention,will be described, reference being had to the accompanying drawings, inwhich:

Figure l is an elevational diagrammatic view of an assembly of a rod ofthe ion-exchange material between two columns of mercury for the passageof an electric current therethrough;

Fig. 2 is an elevational diagrammatic cross-section of a cell containinga diaphragm of the ion-exchange material therein as a separator orbarrier between two electrolyte solutions;

Fig. 3 is a visualized detail cross-section of a submicroscopic portionof the ion-exchange medium illustrative of the coherent solid structurethereof and of the intervening continuous gel water dispersedtherethrough and occluded therein, which are of the order of moleculardimensions; and

Fig. 4 is a graph representing the variation in elective resistance ofan ion-exchange medium of this invention with respect to alternatingelectric current of differing frequencies.

EXAMPLE l Preparation of membranes of phenol sulfonic acid-formaldehydeThe impregnating, low molecular weight polymer was prepared as follows:

Pants by weight Aqueous phenol sulfonic acid (65%) 50' Aqueousformaldehyde (35.4%) 24.7

The acid and the formaldehyde are shaken together and partiallypolymerized at 50 1C. in a closed container (to retain the moisture andformaldehyde). This precuring requires lVz to 2 hours after which theviscous mixture was used to impregnate reinforcing webs such as Saran,Vinyon, glass cloth, and similar materials resistant to strong acids. Itwas poured into a mold to form the cast disks. The curing (until thepolymer turned dark brown or black) was carried out at JC. in a closedsystem and in the presence of moisture. This process required from twohours to two days depending upon the quantity and geometry of thepolymerizing mass.

The special characteristics of the cured material both cast andimpregnated have been entered into the appended table. Precured materialwas preserved in a refrigerator at 5 C. for weeks at a time with nodeleterious eect.

Before using, the diaphragm was conditioned by soaking in water to bringthe water content to the saturation Value and thereafter maintained inwet condition throughout, for purposes of testing and use. A similarprocedure was followed in all of the following examples.

In the course of measuring the conductance of the diaphragm, it wasfound that the specific conductivity (1.4 l0*l ohm*1 cmrl) of thediaphragm in equilibrium with l N hydrochloric acid was greater thanthat of the 1 N hydrochloric acid (O.36 10-1 ohm-1 cmrl) itself.

It may also be observed that in preparing the ionexchange materials ofthe above and following examples (and also of organic polymericion-exchange materials in general, in accordance with the presentinvention) the time and/or temperature and other conditions of curingmay be considerably extended Without substantially altering, theelectrical and/ or surface characteristics of the. resin solong as theWater component is maintained.

EXAMPLE 2 Preparation of molded diaphragms of Amberlite IRC-50 AmberliteIRC-50 is identied by the maker as a synthetic cation-exchanger in theform of white opaque in fournn'nutes.v Alow moleculanweight polymer `wasobtained by heating to 40 C. forabout forty-veminutes. This polymer wasthen usedto impregnate Saran and to prepare cast diaphragms. for thecast material were 75 C. and twelve hours in the presence of moisture.The curing of impregnated material was done at a higher temperature, 90C., and also in the presence of moisture.

TABLE Oharacteris- Capacity tlc concen- Conductivity Moisture(Milliequiv- K ave Material Form tration of structure percent of alentsper (order of potential (ohms1 cm.-1) bone-dry gram magni- (millivolts)material bone-dry tude) material) @est +55 o. 9-14 10-1 114 1. 5-1. 7 710-2 Strongly amd caliomxchngef f Example L {impregnated seran +51 4. 55. s x 10-Aq 114 1. 5-1. 7 7 10-2 weakly acid cation-exchanger ofExample 2 feast'.j +29. 2 g 13g i0 3 X 10-16 0 1 '10* Strongly basi@amon'exchaugef 0f Example 3 (impregnated Saran a2. 4. 5-5. 5 1o-2 121 s.o 3 10-1 strongly acid cation-exchanger of Example 4 east +16. 3. 5 X10-2 45 l. 5-2 10'1-10-2 [strongly basic anion-exchanger 0f Example 5.do 52. 4. 7 X 10-2 58 0. 8-1. 4 10-1-10-2] beads exhibiting theextremely high capacity of 10.0- EXAMPLE 4 10.2 milli-equivalents perdry gram deriving its exchange capacity form weakly acid carboxylic acidgroups and preparano gggieoqfaphmgms 0f was used in the preparation of acast disk as follows:

Parts Amberlite IRC-50 (containing 20% water) 50 Polystyrene solution inbenzene [solution]) 50 The resin is pulverized in a hammer mill, sievedto liner than 100 mesh, made into a slurry with the polystyrenesolution, transferredto thevv mold, and cured at 50 C. The tnal product,containing 20% Water on the basis of the weight of Wet resin, aslindicated above, accordingly contained 25% water on the basis of theWeight of dry resin.

In an alternate procedure, 50 parts of Amberlite IRC-50, with about 27%moisture and ner than 100 mesh, were mixed with 50 parts of a 25%solution of polystyrene in benzene, poured intoV a 3.5 inch vPetri dishand allowed to cure, as above.

In general, the kuse of electrically non-conducting inert binders forpowdered resinous ion-exchangersl such as the polystyrene of thisexample, reduces inherently the conductivity of the cast or moldedproducts. While products containing moderate amounts of such binders maybe useful for many purposes, excessive amounts (eg. amounts exceeding30% by weight of the dry exchangematerial), usually cause such anincrease in electrical resistance as to render the products useless forthe purposes of this invention.

Satisfactory diaphragms have also been molded using this type of binderand, for example heat (120 C.), pressure (2500 lbs/sq. in.), and thirtyminute time of curing. Thus an alternative procedure, for forminglstructuresv comprising granules of :an ion-exchange resin and a bindertherefor, is to combine the granules (containing at least 15% Water) andthe binder material, and effect solidification ofthe binder materialwith the granules embedded therein,under conditions substantiallypreventive of the escape` of water from the granules.

EXAMPLE 3 Preparation of melamine-guanidine formaldehyde diaphragmsParts Melaminev 126 Guanidine carbonate 90 Aqueous formaldehyde (35.4%)243 Aqueous hydrochloric `acid (37%) 162 'I'he melamine and guanidinecarbonate were combinedwith the acidfand the formaldehyde was added tothe mixture. At 110 C. the material polymerized with- The (stronglyacid) sulphonated copolymer of styrene and divinylbenzene, which isdescribed by W. C. Bauman and I. Eichhorn under thename of Dowex 50 inthe Journal of the AmericanChemical Society, volume 69, page 21830(1947) and also by DAlelio in U.S. Patent 2,366,007, was used in thepreparation of a cast disk as follows:

The commercial resin, obtained as 100-200 mesh beads was cast 'intodisks by means of heat and a binder. The

binder used vwas phenolsulfonic acid formaldehyde.

Parts Dowex 50 (calculated as bone dry) 100 40 Aqueous phenolsulfonicracid (65%) 25 Aqueous formaldehyde (35.4%) 12.5

The phenolsulfonic acid and formaldehyde Wereshaken together and addedtothe Dowex 50. The resulting slurry was transferred [poured] into a moldand cured at 105 C. in an atmosphere saturated with water vapor.

[EXAMPLE 5 Preparation of molded diaphragms of Amberlite IRA-400 Thiscommercial resin, obtained as 20440 mesh beadsV was cast into disks bymeans of. heat and a binder. The binder used was melamine-guanidineformaldehyde.

5 Parts Amberlite IRA-400 (containing 30% of water) 100 The lowmolecular weight melamine guanidine formaldehyde polymer prepared inaccordance with the procedure of Example 3 20 Water 80 The binder wasdissolved in the water by heating, and

the resulting viscous solution added tothe beads of Amberlite IRA-400.This slurry was poured into a mold and cured at C. in an atmospheresaturated with water vapOrJL The curing conditionsv 9 EXAMPLE 6Electrolysis in the ion-exchange medium Parts Sulfuric acid (95.5%) 100Phenol 79 Formaldehyde (37%, in water) 129 The phenol was melted andheated to 95 C., the sulfuric acid added land the mixture heated at 140C. for two hours and then cooled to`15 C. The phenol-sulfuric acidmixture was added to the formaldehyde which had been cooled to C.,additional cooling being provided to keep the temperature below 20 C.The resulting mixture may be stored for weeks fat C.

The unpolymerized liquid was poured into a cylindrical glass mold andpolymerized at 60 C. until dark in color. The rod was conditioned bysoaking in distilled water until substantially all water-solublereagents were removed. The resulting cation exchange rod 1 (Fig. 1), 5.2cm. long and 1.2 cm. in diameter, was mounted between the rods of glasstubes 2, 3, in a rubber tubing 4 as shown. The glass tubes 2, 3, werefilled with mercury at 5 and 6 into which were dipped platinumelectrodes 7 and 8. A direct current of 4 milliamperes developed when apotential of 6 volts was imposed on the system, the current beingcarried ionically in the cast rod, for a constant D.C. potential varyingslightly with time giving rise to an evolution of hydrogen gas at themercuryexchanger interface adjacent to the positive terminal. Much ofthe oxygen combined with the mercury at the interface to give oxides ofmercury. If the rod is kept wet with water, the electrolysis may becontinued. Measuring the volume of evolved hydrogen at constant pressuregives a measure of the number of coulombs passed by the electricalcircuit. The system may be used as a convenient coulombmeter.

Upon `closing the circuit an instantaneous very high current of 0.04iampere was observed which dropped to the steady value given above. Thisunusual behavior illustrates the novel nature of this type ofelectrolysis.

EXAMPLE 7 The novel electrical properties of cast ion-exchange materialsfor the measurement of frequency of an electric field Parts Sulfuricacid (95.5%) 8 Phenol 100 Formaldehyde (37%) 130 The phenol and sulfuricacid were mixed together, heated at 130 C. for three hours, cooled to 15C. and added to the formaldehyde which had been chilled to 0 C.,additional cooling being provided to keep the temperature below 20 C.The mixture was a reddish-brown, oily liquid. It may be stored for weeksat 5 C. The liquid was poured into a cylindrical glass mold andpolymerized `at 60 C. until black in color. The resulting rod wasconditioned by soaking in distilled Water and then in 2 N HC1 andfinally was washed free from HCl with distilled water. The resistance ofthis Water-satunated rod was measured in a direct current, and inalternating currents of varying frequencies. It was found to decrease ata rate of 4.7 103 ohm-seconds per cycle in the range of 1,000 to 20,000cycles per second, the variation being shown in the gnaph of Figure 4.This method permits one to measure the frequency of an appliedalternating current by measuring the resistance of a calibrated resinrod.

EXAMPLE 8 Continuous ion-exchange between two electrolytes PartsSulfuric acid (97%) 10S Phenol 100 Formaldehyde (37% in water) 130 Thephenol and sulfuric acid were mixed together and heated #at 120 C. forfour hours, cooled to 15 C. and added to the formaldehyde which had beencooled to 0 C. Additional cooling was provided to keep the temperaturebelow 20 C. The mixture may be stored for weeks at 5 C. withoutexcessive polymerization.

A rod was made of this material by pouring it into a cylindrical glassmold and curing at 60 C. until solid and dark in color. The resultingresin cylinder was drilled out on a lathe to give a tube 4.5 cm. long,0.9 cm. outside diameter and 0.3 cm. inside diameter. This tube wasmounted in a glass cell. A solution of 0.02 N CaCl2 was circulatedthrough the inside of the tube at 12.5 cc./min. for 24 hours and asolution of 0.2 N NaCl on the outside at 2.5 cc./min. for 24 hours.Transfer of cations took place almost to the exclusion of anions.

A reinforced diaphragm was made by impregnating Vinyon lter cloth withunpolymerized exchanger and curing at C. for 10 minutes in a moisturesaturated atmosphere. The resulting diaphragm was suitably mounted in aglass vessel to give a vertical partition. A 0.1 N CaClz solution wasput in one compartment and a 0.1 N KNO3 solution in the other. The rateof exchange of calcium ions between solutions was l.6 l02 mg. per ft.hour. This was considerably greater than the nate of exchange ofchloride ions which was 2.5 X 103 mg. per ft. hour.

EXAMPLE 9 Application of ion exchange diaphragms to the sodium chlorideelectrolysis cell Preparation of ion-exchange diaphragm: Parts Sulfuricacid (95.5%) 141 Phenol Formaldehyde (37% in water) 180 The sulfuricacid wlas added to the phenol at 95 C. and the mixture heated at C. fortwo hours and cooled to room temperature. The formaldehyde was cooled to0 C. and the mixture of phenol and sulfuric acid added, additionalcooling being provided to keep the temperature of the mixture below 20C. The temperature was then reduced to 5 C., yat which temperature themixture may be stored for weeks without polymerization. The mixture wasa viscous, oily liquid of reddishamber color.

The mixture was poured into a cylindrical glass mold and heated at 50 C.until solid and dark in color. The resulting resin cylinder was saWedinto disks, and the disks were washed in distilled Water until the washwater was sulfate free and'one of the disks 9 was then used in auelectrolysis cell 10 diagrammatically shown in Fig. 2.

The diaphragm was 0.3 cm. in thickness with an area of 0.7 cm?. Theanolyte was a saturated NaCl solution, the catholyte 25 cc. of 0.16 NNaOH, the current 20 milliamperes at 6 volts.

At the end of 24 hours there was no chloride in the catholyte (silvernitrate test) and the concentration of NaOH in a total volume of 22 cc.was then 1.52 N.

We have found the conductance of this cast phenolsulfuric acidformaldehyde diaphragm to be 33x10-2 ohms-1 cm.1.

Hence, this cell is superior to the conventional diaphragm caustic cellin producing chloride yfree caustic. It is superior to the mercury cellin producing chloride free caustic in that it involves no mercury.

EXAMPLE l0 Permselective diaphragms in the construction of primaryelectric cells Preparation of the diaphragm:

Parts Triamino triazine (melamine) 126 Guanidine carbonate 90Hydrochloric acid (37% in water) 135 Formaldehyde (37% in water) 300 TheguaUidinecarbOnateand triamino triazine (melamine) were, mixed ,togetherandthe hydrochloric acid added andthen ,the formaldehyde. A piece ofVinyon cloth was impregnated in the warmed unpolymerized mixture andcured at 110 C. for 10 hours. The polymer was colorless and transparent.The impregnated cloth was converted to thev sulfate form by soaking inan. excess ot 0.5 N Na2SO4 solution, the excess solution was removed andthe diaphragm then mounted as a vertical partition in a glass vessel.One cornpartmentwas lled with a saturated solution of zinc sulfate andtheother with a saturated solution of copper sulfate. A zinc plate wasvimmersed in the zinc sulfate solution and a copper plate inthe coppersulfate solution. After four days there .was no visible coatingof copperon the Zinc electrode. The areaof the diaphragm was 6 square inchesandthe thickness was `0.04 inch. The open circuit voltage. at 22 C. was1.050 volts and did not vary more than 2% in the range -8 C. to 25 C.The internal resistance of the cell was 24 ohms at 22 C. Theinternaltresistance of the cell. was decreased to 7 ohms by substitutingcupric and zinc. chlorides with a diaphragm conditioned with, 0.5 NNaCl. This type of cell is commonly referred to as a Daniel cell.

We claim:

l. As an article of manufacture, a solid unfractured structure vhavingat least two dimensions each in excess of 0.25 inch, and lcomprising asan essential part extending substantially throughout said structure, apredominant amount of an ion exchangey resin which comprises: aninsoluble infusible synthetic organic polymeric matrix, dissocialbleionic groups chemically bonded to saidrn-atrix, and water in gelrelationship with said matrix; said groups having, a dissociationconstant of at least 10-5 and being present in an amo-unt. of at least0.3 milliequivalent per` graml of dry resin, and said-water beingpresent in an amount of at least 15% of the weight of the dry resin.

2. As an articleof manufacture, a solid unfracturedl sheet `havingtwodimensions each in excess of 0.25 inch, and comprisingas an essentialpart extending substantially throughout said sheet, a predominant amountof an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded to said matrix, and ywater in gel relationship with said matrix;said groupshaving a dissociation constant of at least 10-5 and beingpresent in an amount of at least 0.3V milliequivalent per gram of dryresin, andsaid Iwater being present in an amount of at least of theweight of the dry resin..

3. As an article of manufacture, a solid unfractured membrane[structure] having at least two dimensions eachV in excess of 0.25 inch,and comprising as an essential part extending substantially throughoutsaid membrane [structurel a predominant amount of an ion exchange resinwhich comprises: an insoluble infusible synthetic organic` polymericmatrix, dissociable ionic groups chemically bonded to said matrix, andwater` in gel relationship with said matrix; said groups having adissociation constant (K) of at least 10w5, said groups being present inan amount of at least 3.0` milliequivalents per gram of dry resin whenKis between 10*5 and l0-3 and in an amount of at least 0.3milliequivalent per gram of dry resin when K is 10-3 or greater; andsaid water being present in an amount of at least l5 percent of theweight of the dry resin.

4. The article defined by claim 3 wherein the water is present in anamount of at least 25 percent of the weight of dry resin.

5. As an article of manufacture, a solid unfractured structure having atleast two dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure, apredominant amount of a homogeneous continuous phase of an ion ex.change resin which comprises: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groupsv chemically bonded to saidmatrix, and Water in gel relationship with said matrix; said groupshaving a dissociation constant (K) of at least 10ml, said groups beingpresent in an amount of at least 3.0 milliequivalent per gram ofdryresin when K is between 10-5 and 10-3 and in an amount of-at least0.3 milliequivalent per gram of dry resinwhen vK-islO-3 or greater; andsaid water being presentin an; amount of at least l5 percent of theweight of the dry resin.

6. The article defined by claim 5 wherein `the water is present in anamount of at least 25 percent of the weight of dry resin.

7; As an article ofrnanufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as yan essentialpart extending substantially throughout said sheet, a predominant amountof an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric. matrix, dissociable ionic groups chemicallybonded to `said matrix, and water in gel relationship with said matrix;said groups having a dissociation constant (K) of at least 105, saidgroups being present in an amount of atleast 3.0 milliequivalents pergram of dry resin when K is -between 10-5 and 10-3 and in an amount ofat least 01.3 milliequivalent per gram ot dry resin when K is l0h3 orgreater; and `said water being present in an amount of 'at least l5percent of the weight of the dry resin.

8. The article defined by claim `7 wherein the ion exchange resin is ahomogeneous continuous phase.

9. The article defined by claim 8 wherein the Water is present in anamount of at least 25 percent of the weight of dry resin.

10. The article deiined by claim 7 wherein the water is present in anamount of at least 25 percent of the weight of dry resin.

l1. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising in combination areinforcing web and as an essential part extending substantiallythroughout said sheet, a` predominant amountof an ion exchange resinwhich comprises: an insoluble infusible synthetic organic polymericmatrix, `dissociable ionic groups chemically bonded to said matrix, andwater in Vgel relationship with *at least 15 percent of the weight ofdry resin.

l2. The article deined by claim ll wherein the ion exchange resin is ahomogeneous continuous phase.

13. The article detined by claim l2 wherein the water is present in anamount of at least 25 percent lof the weight of dry resin.

14. The article defined vby claim 11 wherein the water is present in anamount of atleast 25 percent of the weight of dry resin.

l5. As an article of manufacture, a solid unfractured sheet havingtwodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof a homogeneous continuous phase of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociableionic groups chemically bonded to said matrix, and water ingel relationship with said matrix; said groups having adissociationconstant of at least 105 and being present in an amount of at least 0.3

milliequivalent per gram of dry resin, and said water being- `present inan amount of at least 15% of the weight of the each in excess of 0.25inch, and comprisingas an essential f part extendingn substantially;throughout said [structure] eases membrane, a predominant amount ofparticles of an ion exchange resin, and an insoluble binder therefor,said resin comprising: an insobluble infusible synthetic organicpolymeric matrix, `dissociable ionic groups chemically bonded to saidmatrix, and water in gel relationship with said matrix; said groupshaving a dissociation constant (K) of at least 10-5, said groups beingpresent in an amount of at least 3.0 milliequivalents per gram of dryresin when K is between 10-5 and 10-3 and in an amount of at least 0.3milliequivalent per gram of dry resin when K is l-3 or greater; and saidWater being present in an amount of at least 25 percent of the weight ofthe dry resin.

17. The article dened by claim 16 wherein the binder is a non-conductingmaterial.

18. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountoi particles of an ion exchange resin, and an insoluble binder therefor,said resin comprising: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groups chemically bonded to saidmatrix, and water in gel relationship with said matrix; said groupshaving a dissociation constant (K) of at least -5, said groups beingpresent in an amount of at least 3.0 milliequivalents per gram of dryresin when K is between l0'-5 and 10-3 and in an amount of at least 0.3milliequivalent per gram of dry res-in when K is l03 or greater; andsaid water being present in an amount of at least 25 percent of theweight of the dry resin.

19. The article deiined by claim 18 wherein the binder is anon-conducting material.

20. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure, apredominant amount of the combination of particles of an ion exchangeresin and a binder which is an ion exchange resin, each of said exchangeresins comprising: an insoluble infusibile synthetic organic polymericmatrix, dissociable ionic groups chemically bonded to said matrix, andwater in gel relationship with said matrix; said groups having adissociation constant (K) of at least 10r5, said groups being present inan amount of at least 3.0 milliequivalents per gram of dry resin when Kis between 10-5 and 10-3 and in an amount of at least 0.3milliequivalent per gram of dry resin when K is l03 or greater; and saidwater being present in an amount of at least 25 percent of the weight ofthe dry resin.

21. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, `a predominantamount of the combination of particles of an ion exchange resin and abinder which is an ion exchange resin, each of said exchange resinscomprising: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded to said matrix, and water ingel relationship with said matrix; said groups having a dissociationconstant (K) of at least 10i-5, said groups being present in an amountof at least 3.0 milliequivalents per gram of dry resin when K is betweenl0"5 and 10-3 and in an amount of at least 0.3 milliequivalent per gramof dry resin when K is l0n3 or greater; and said water being present inan amount of at least 25 percent o-f the weight of the dry l resin.

22. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure, apredominant amount of an ion exchange resin which comprises: aninsoluble infusible synthetic organic polymeric matrix, dissociableionic groups chemically bonded to said matrix, and water in gelrelationship with said matrix; said groups 14 having a dissociationconstant of at least 10*3 and being present in an amount of at least 0.8milliequivalent per gram of dry resin, and said water being present inan amount between about 58 and 138 percent of the weight of the dryresin.

23. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded to said matrix, and Water in gel relationship with said matrix;said groups having a dissociation constant of at least 10-3 and beingpresent in an amount of at least 0.8 milliequivalent per gram of dryresin, and said water being present in an amount between about 58 and138 percent of the weight of the dry resin.

24. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure, apredominant amount of an ion exchange resin which comprises: aninsoluble infusible synthetic organic polymeric matrix, dissociableionic groups chemically bonded to said matrix, and water in gelrelationship with said matrix; said groups being selected from the classconsisting of sulfonate, quaternary ammonium, guanidyl, anddicyandiamidino, said groups being present in an amount of at least 0.8milliequivalent per gram of dry resin; and said water being present inan amount between about 5 8 and 138 percent of the weight of dry resin.

25. The article delined by claim 24 wherein the ion exchange resin is ahomogeneous continuous` phase.

26. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded to said matrix, and water in gel relationship with said matrix;said groups being selected from the class consisting of sulfonate,quaternary ammonium, guanidyl, and dicyandiamidino, said groups beingpresent in an amount of at least 0.8 milliequivalent per gram of diyresin; and said water being present in an amount between about 58 and138 percent of the weight of dry resin.

27. The article deiined by claim 26 wherein the ion exchange resin is ahomogeneous continuous phase.

28. As an article of manufacture, a solid unfractured sheet having twoidimensions each in excess of 0.25 inch, and comprising in combination areinforcing web and as an essential pant extending substantiallythroughout said sheet, a predominant amount of an ion exchange resinwhich comprises: -an insoluble infusible synthetic organic polymericmatrix, dissociable ionic groups chemically bonded to said matrix, andwater in gel relationship with said matrix; said groups being selectedfrom the class consisting of sulfonate, quaternary ammonium, guanidyl,and dicyandiamidino, said groups being present in an amount of at least0.8 milliequivalent per gram of dry resin; and said water being presentin an amount between about 58 .and 138 percent of the weight of dryresin.

29. The article deiined by claim 28 wherein the ion exchange resin is ahomogeneous continuous phase.

30. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure, apredominant amount of particles of an ion exchange resin, and aninsoluble binder therefor, said resin comprising: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded Ito said matrix, and water in gel relationship with said matrix;said groups being selected from the class consisting of sulfonate,quaternary ammonium, guanidyl, and dicyandiamidino, said groups beingpresent in an amount of at least 0.8 rnilliequivalent per gram of dryresin; and said water being present in an amount between about 58 and138 precent of the weight of dry resin.

31. The article deined by claim 30 wherein the binder is anon-conducting material.

32. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof particles of an ion exchange resin, and an insoluble binder therefor,said resin comprising: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groups chemically bonded lto saidmatrix, and water in gel relationship with said matrix; said groupsbeing selected from the class consisting of sulfonate, quaternaryammonium, guanidyl, and dicyandiamidino, said groups being present in anamount of at least 0.8 milliequivalent per gram of dry resin; and saidwater being present in an amount between about 58 and 138 percent of theweight of dry resin.

33. The article defined by claim 32 wherein the binder is anon-conducting material.

34. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure apredominant amount of the combination of particles of an ion exchangeresin and a binder which is an ion exchange, resin, each of saidexchange resins comprising: an insoluble infusible synthetic organicpolymeric mixture, dissociable ionic groups chemically bonded to saidmatrix, and water in gel relationship with said matrix; said groupsbeing selected from the class consisting of sulfonate, quaternaryammonium, guanidyl, and dicyandiamidino, said groups being present in anamount of at least 0.8 milliequivalent per gram of dry resin; and saidwater being present in an amount between about 8 and 138 percent of theweight of dry resin.

35. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof the icombination of particles of an ion exchange resin and a binderwhich is an ion exchange resin, each of said exchange resins comprising:an insoluble infusible synthetic organic polymeric matrix, dissociableionic groups chemically bonded to said matrix, and water in gelrelationship with said matrix; said groups being selected from the classconsisting of sulfonate, quaternary ammonium, guanidyl, yanddicyandiamidino, said groups being present in an amount of at least 0.8milliequivalent per gram of dry resin; and said water being present inan amount between about 58 and 138 percent of the weight of dry resin.

36. As an article of manufacture, a solid unfractured structure havingat least two dimensions each in excess of 0.25 inch, and comprising asan essential part extending substantially throughout said structure, apredominant amount of an ion exchange resin which comprises: aninsoluble infusible synthetic organic polymeric matrix, dissociableionic groups chemically bonded to said matrix, and water in gelrelationship with said matrix; said groups being selected from the'class consisting of sulfonate, quaternary ammonium, guanidyl, anddicyandiamidino, said groups being present in an amount of at least 0.3milliequivalent per gram of dry resin; and said water being present inan amount of at least 25 percent of the weight of dry resin.

37. As an article of manufacture, a solid unfractured sheet having twodimensions each in excess of 0.25 inch, and comprising as `an essentialpar-t extending substantially` throughout said sheet, a predominantamount of au ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded to said matrix, and water in gel relationship with said matrix;said groups being selected from the class consisting of sulfonate,quaternary ammonium, guanidyl, and dicyandiamidiuo, said groups beingpresent in an amount of at least 0.3 milliequivalent per gram of dryresin; and said water being present in an amount of at least 25 percentof the weight of dry resin.

38. As an article of manufacture, a solid unfractured' sheet having Vtwodimensions each in excess of 0.25 inch, and comprising in combination areinforcing web and as an essential part extending substantiallythroughout said sheet, a predominant amount of an ion exchange resinwhich comprises: an insoluble infusible synthetic organic polymericmatrix, dissociable ionic groups chemically bonded to said matrix, andwater in Igel relationship with said matrix; said groups being selectedfrom the class consisting of sulfonate, quaternary ammonium, guanidyl,and dicyandiamindino, said groups being present in an amount of at least0.3 milliequivalent per gram of dry resin; and said water being presentin an amount of at least 25 percent of the weight of dry resin.

39. As an article of manufacture, a solid unfractured sheet having twodimensions each i-n excess of 0.25 inch, and comprising as an essentialpart extending substantially throughout said sheet, a predominant amountof particles of an ion exchange resin, and an insoluble binder therefor,said resin comprising: an insoluble inusible synthetic organic polymermatrix, dissociable ionic groups chemically bonded to said matrix, andwater in gel relationship with said matrix; said lgroups being selectedfrom the class consisting of sulfonate, quaternary ammonium, guanidyl,and dicyandiamidino, said groups being present in an amount of at least0.3 milliequivalent per gram of dry resin; and said water being presentin an amount of at least 25 percent of the weight of dry resin.

40. The article defined by claim 26 wherein the ion exchange resin is aphenol sulfonate-aldehyde condens-ation product.

41. The :article defined by claim 29 wherein the ion exchange resin is aphenol sulfonate-aldehyde condensation product.

42. The article dened by claim 26 wherein the ion exchange resin is asulfonated copolymer of styrene and divinyl benzene.

43. The article deiined by claim 37 wherein the ion exchange resin is asulfonated copolymer of styrene and divinyl benzene.

44. The article defined by claim 32 wherein the ion exchange resin is asulfonated copolymer of styrene and divinyl benzene.

45. The article delined by claim 39 wherein the ion exchange resin is asulfonated copolymer of styrene and divinyl benzene.

46. The article `defined by claim 26 wherein the ion exchange resincomprises a copolymer of styrene and divinylbenzene having quaternaryammonium groups bonded to the aromatic nuclei.

47. The article defined by claim 37 wherein the ion exchange resincomprises a copolymer of styrene and divinylbenzene having Quaternaryammonium groups bonded to the aromatic nuclei.

48. The article defined by claim 32 wherein the ion exchange resincomprises a copolymer of styrene and divinylbenzene having quaternaryammonium groups bonded to the aromatic nuclei.

49. The article defined by claim 39 wherein the ion exchange resincomprises a copolymer of styrene and divinylbenzene having quaternaryammonium groups bonded to the aromatic nuclei.

50. The `article defined by claim l0 wherein the poly- 17 meric matrixcomprises a copolymer of styrene and divinlylbenzene.

51. The article defined by claim 26 wherein the ion exchange resin is amelamine guanidine condensation product.

52. In the method of forming 1a solid unfractured structure having atleast two dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin which comprises: aninsoluble infusible synthetic organic polymeric matrix, dissociableionic groups chemically bonded to said matrix, `and water in gelrelationship with said matrix; said groups having a dissociationconstant of at least l*5 and being present in lan amount of at least0=.3 milliequivalent per gnam of dry resin, and said water being presentin an amount of at least 15% of the weight of dry resin, the step offorming said solid structure under conditions substantially preventiveof the escape of water.

53. The method of forming a solid unfractured structure having iat leasttwo dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin, comprising the steps of:forming an aqueous dipersion of material polymerizable into an ionexchange resin which comprises an insoluble, infusible synthetic organicpolymeric matrix and dissociable ionic groups chemicallf)l bonded tosaid matrix, said groups having a dissociation constant in excess of *5and being present in the amount of at least 0.3 milliequivalent per gramof dry resin said dispersion containing water in `an vamount of at leastof the Weight of dry resin; and polymerizing said material to theinsoluble infusible stage under conditions substantially preventive ofthe escape of Water from said dispersion.

54. The method of forming a solid unfractured structure having at leasttwo dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin, comprising the steps of:forming an aqueous dispersion of material polymerizable into an ionexchange resin which comprises an insoluble infusible synthetic organicpolymeric matrix and dissociable ionic groups chemically bonded to saidmatrix, said groups having a dissociation constant (K) in excess of10-5, said `groups being present in `an amount of at least 3.0milliequivalents per gnam of dry resin when K is between 10-5 and 10-3and in an amount of at least 0.3 milliequivalent per gram of dry resinwhen K is 103 or greater; said `dispersion containing Water in an amountof at least 25% of the Weight of dry resin; casting said dispersion tothe desired form; Iand polymerizing said material to the insolubleinfusible stage under conditions substantially preventive of the escapeof water from said dispersion.

55. The method of forming a `solid unfractured structure having at leasttwo dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin, comprising the steps of:`forming an aqueous dispersion of material polymerizable into an ionexchange resin which comprises an insoluble infusible synthetic organicpolymeric matrix and dissociable ionic groups chemically bonded to saidmatrix, said groups being selected from the class consisting ofsulfonate, quaternary ammonium, guanidyl, and dicy'andiarnidino, saidgroups being present in a concentration of at least 0.8 milliequivalentper gram of dry resin, said dispersion containing Water in an amountbetween about 58 and 138 percent of the weight of dry resin; castingsaid dispersion to the desired form; and polymepizing said material tothe insoluble infusible stage under conditions substantially preventiveof the escape of water from said dispersion.-

56. The method of forming a solid unfractured structure having at leasttwo dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin, comprising the steps of:combining with a binder a predominant amount of particles of an ion-exchange resin which comprises an insoluble infusible `syntheticorganic polymeric matrix, dissociable ionic groups chemically bonded tosaid matrix, and water in gel relationship with said matrix, said groupshaving a dissociation constant (K) of at least l0-5, said groups beingpresent in an amount of at least 0.3 milliequivalent per grani of dryresin when K is l03 or greater, and said Water being present in anamount of at least 25% of the Weight of dry resin; and forming saidstructure under conditions substantially preventive of the escape ofwater.

57. The method of forming a solid unfractured structure having at leasttwo dimensions each in excess of 0.25 inch, and comprising as anessential part extending substantially throughout said structure apredominant amount of an ion exchange resin, comprising the steps off:combining particles of an ion exchange resin with an aqueous dispersionof material polymerizable into an ion exchange resin, each of saidresins comprising an insoluble infusible synthetic o-rganic polymericmatrix, dissociable ionic groups chemically bonded to said matrix, andWater in gel relationship with said matrix, said groups having adisassociation constant (K) of at least 10-5, said groups being presentin `an amount of at least 3.() milliequivalents per gram of dry resinwhen K is between l0*5 and 10-3 and in an amount of at least 0.3milliequivalent per gram of dry resin when K is 103, or greater and saidwater being present in an amount of at least 25% of the Weight of dryresin; casting said mixture to the desired form; and polymerizing thedispersed material to the water insoluble infusible stage underconditions substantially preventive of the escape of water.

58. In an electrolytic system, a pair of compartments, a barrierseparating said compartments, and electrical contacting meanscommunicating with the interior of each of said compartments, saidbarrier comprising as an essential part extending substantiallythroughout, a predominant amount of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded to said matrix and Water ingel relationship with said matrix; said groups having a dissociationconstant greater than 10-5 and being present in an amount of at least0.3 milliequivalent per gram of dry resin, and said Water being presentin an amount of at least 15% of the weight of dry resin.

59. In an electrolytic system, a pair of compartments, a barrierseparating said compartments, and electrical contacting meanscommunicating with the interior of each of said compartments, saidbarrier comprising `as an essential part extending substantiallythroughout, a predominant amount of an ion sxchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded to said matrix and water ingel relationship with said matrix; said groups having a dissociationconstant (K) greater than 10-5, said groups being present in an amountof at least 3.0 milliequivalents: per gram of dry resin for groupshaving a K between 10-5 and l0-3 and in an amount of at least 0.3milliequivalent per gram ot dry resin for groups having a K of l03 orhigher; and said Water being present in an amount of at least 25% of theweight of dry resin.

60. The system defined by claim 59 wherein the ion exchange resin is ahomogeneous continuous phase.

6l. An electrodialysis cell comprising a pair of compartments, a barrierseparating said compartments and electrical contacting meanscommunicating with the in-4 terior of each of said compartments, saidbarrier comprising as an essential part extending substantiallythroughout, a predominant amount of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded lo said matrix and water ingel relationship with said matrix; said groups having a dissociationconstant (K) greater than 10-5, said groups being present in an amountof at least 3.0 milliequivalents per gram of dry resin for groups havinga K between 10-5 and l0-3 and in an amount of at least 0.3milliequivalent per gram orf `dry resin lfor groups having a K of l"3 orhigher; and said water being present in an amount of at least 25% of theweight of dry resin.

`62. An electrodiialysis cell comprising a pair of compartments, abarrier separating said compartments and electrical contacting meanscommunicating with the interior of each of said compartments, saidbarrier cornprising as an essential part extending substantiallythroughout, `a predominant amount of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded to said matrix and water ingel relationship with said matrix; said groups being selected from theclass consisting of sulfonate, quaternary ammonium, guanidyl anddicyandiamidino and being present in an amount of at least 0.8milliequivalent per gram of dry resin, and said water being present inan amount of be-tween about 58 and 138 percent of the weight of dryresin.

63. An electrodialysis cell comprising an anode compartment and a firstelectrode therein, a cathode compartment and a second electrode therein,and a barrier separating said compartments, said barrier comprising asan essential part extending substantially throughout, a predominantamount of an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymeric matrix, dissociable ionic groups chemicallybonded to said matrix and water in gel relationship with said matrix;said lgroups having a dissociation constant (K) greater than -5, saidgroups being present in an amount of at least 3.0 milliequivalents pergram of dry resin for groups having a K between 10-5 and l0*3 and in anamount of at at least 0.3 milliequivalent per gram of dry resin forgroups having a K of 10-3 or higher; and said water being present in anamount of at least 25% of the weight of dry resin.

64. An electrodialysis cell comprising an anode compartment and a iirstelectrode therein, a cathode compartment and a second electrode therein,and a barrier separating said compartments, said barrier comprising asan essential part extending substantially throughout, a predominantamount of an ion exchange resin which comprises: an insoluble infusiblesynthetic organic polymerio matrix, dissociable ionic groups chemicallybonded to said matrix and water in gel relationship with said matrix;said groups being selected from the class consisting of sulfonate,quaternary ammonium, guanidyl and dicyandiamidino and being present inan amount ofv at least 0.8 milliequivalent per gram of dry resin, andsaid water being present in an amount of between about 58 and 138percent of the weight of dry resin.

`65. In an electromot-ive cell adapted to provide a source ofelectromotive force between a pair of electrodes, a banier between saidelectrodes, said barrier comprising as an essential part extendingsubstantially throughout, a predominant amount of an ion exchange resinwhich comprises: an insoluble 4infus-ible synthetic organic polymericmatrix, dissociable ionic groups chemically bonded to said matrix andwater in gel relationship with said matrix; said groups having adissociation constant (K) greater than 10x5, said groups being presentin an amount of at least 3.0 mlliequivalents per gram of dry resin forgroups having a K between 10-5 and 10-3 and in an amount yof at least0.3 milliequivalent per gram of dry resin-forgroups having aK of 11)*320 or higher; and said water being present in an amount of at least 25%of the Weight of dry resin.

66. In an electromotive cell adapted to provide a source ofelectromotive forcev between a pair of electrodes, a barrier betweensaid electrodes, said barrier comprising asY an essential part extendingsubstantially throughout, a predominant amount of an ion exchange resinwhich comprises: an insoluble infusible synthetic organic polymericmatrix, dissociable ionic groups chemically bonded to said matrix andwater in gel relationship with said matrix; said groups being selectedfrom the class consisting of sulfonate, quaternary ammonium, guanidyland dicyandiamidino and being present in an amount of at least 0.8milliequivalent per gram of dry resin, and said water being present inan amount of between about 58 and 138 percent of the weight of dryresin.

67. In a Daniel cell, a barrier separating the two solutions, saidbarrier comprising as an essential part extending substantiallythroughout, a predominant amount of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemicallyy bonded to said matrix and water ingel relationship with said matrix; said groups having a dissociationconstant (K) greater than 10-5, said groups being present in an amountof at least 3.0 milliequivalents per gram of dry resin for groups havinga K between 105 and 10-3 and in an amount of at least 0.3milliequivalent per gram of dry resin for groups having a K of 10-3 orhigher; and said water being present in an amount of at least 25% of theweight of dry resin.

68. In a Daniel cell, a barrier separating the two solutions, saidbarrier comprising as an essential part extending substantiallythroughout, a predominant amount of an ion exchange resin whichcomprises: an insoluble infusible synthetic organic polymeric matrix,dissociable ionic groups chemically bonded to said matrix and water ingel relationship with said matrix; said groups being selected from theclass consisting of sulfonate, quaternary ammonium, guanidyl anddicyandiamidino and being present in an amount of at least 0.8milliequivalent per gram of dry resin, and said water being present inan amount of between about 58 and 138 percent of the weight of dryresin.

69. A method of transferring ions of one charge from 'one electrolyticsolution to another to the substantial exclusion of ions of the othercharge comprising separating said solutions by means of a barrier andpassing adirect electric current in series across said solutions andseparating barrier, said barrier comprising as an essential partextending substantially throughout, a predominant amount of an ionexchange resin which comprises: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groups chemically bonded to saidmatrix and water in gel relationship with said matrix; said groupslhaving a dissociation constant greater than 10-5 and being present in anamount of at least 0.3 milliequivalent per gram of dry resin, and saidwater being present inV an amount of at least 15% of the weight of dryresin.

70. A method of transferring ions of one charge from one electrolyticsolution to another to the substantial exclusion of ions of the othercharge comprising separating said solutions by means of a barrier andpassing a direct electric current in series across said solutions andSeparating barrier, said` barrier comprising as an essentialpartextending substantially throughout, a predominantamount of an ionexchange resin which comprises: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groups chemically bonded to saidmatrixy and water in gel relationship with said matrix; said groupshaving a dissociation constant (K) greater than l05, said groups beingpresent in an amountr of `at least 3.0 milliequivalentsper gram of dryresin4 for groupsvhavingt a K between 10"5 and 10-3 and inanamQuntQfgatleast'L 0.3 milliequivailent per gramv of dry resigrnfollgroups,1

having a K of -3 or higher; and said water being present in an amount ofat least 25% of the weight of dry resm. A

71. A method of transferring ions of one charge from one eleotrolyticsolution to another to the substantial exclusion of ions of the othercharge comprising separating said solutions by means of a barrier andpassing a direct electric current in series across said solutions andseparating barrier, said barrier comprising as `an essential partextending substantially throughout, a predominant amount of an ionexchange resin which comprises: an insoluble infusible synthetic organicpolymeric matrix, dissociable ionic groups chemically bonded to saidmatrix and water in gel relationship with said matrix; said groups beingselected from the class consisting of sulfonate, quaternary ammonium,guanidyl and dicyaudiamidino and being present in Yan [amount of atleast 0.8 milliequivalent per gram of dry resin, and said water beingpresent in an amount of between about 58 'and 138 percent of the weight`of dry resin.

72. The method of electrolyzing aqueous solutions of sodium chloride toproduce a sodium hydroxide solution and chlorine, comprising contactingthe solution of sodium `chloride with an anode and one side of thebarrier, contacting the sodium hydroxide solution with `a cathode andthe other side of the barrier, and passing an electric current betweenthe anode and cathode, said barrier comprising as an essential partextending substantially throughout, a predominant amount of a cationexchange resin which comprises: an insoluble infusible synthetic organicpolymeric matrix, ionic groups dissociable into a free mobile cationchemically bonded to said matrix, and water in gel relationship withsaid matrix; said ionic groups having a dissociation constant (K) of atleast 10-5, said ionic groups being present in an amount of at least 3.0milliequivalents per grain of dry resin for groups having a K between105 and 104, and in amount of at least 0.3 milliequivalent per gram ofdry resin for groups having a K of 10-3 or above; and said water beingpresent in an amount of lat least 25 of the weight of dry resin.

References Cited in the le of this patent or the origlnal patent UNITEDSTATES PATENTS `461,965 Souther Oct. 27, 1891 665,625 Amwake Ian. 8,1901 1,176,541 Gibbs Mar. 21, 1916 1,284,618 Dow Nov. 12, 1918 1,557,931Grossmann Oct. 20, 1925 1,926,063 Rossiter et al. Sept. 12, 19331,931,954 Childs Oct. 24, 1933 1,998,539 Gams et al. Apr. 23, 19352,195,196 Wassenegger et al. Mar. 26, 1940 2,204,539 Wassenegger et alJune 11, 1940 2,228,159 Wassenegger et al. Jan. 7, 1941 2,297,837Loughnane Oct. 6, 1942 2,341,907 Cheetham et al Feb. 15, 1944 2,395,825Hesler Mar. 5, 1946 2,434,190 Barnes J-an. 6, 1948 2,448,029 Huested etal Aug. 31, 1948 2,452,624 Zimmermann Nov. 2, 1948 2,500,113 Banks Mar.7, 1950 f 2,500,149 Boyer Mar. 14, 1950 2,546,938 Bauman Mar. 27,. 19512,593,540 Cornwell et -al Apr. 22, 1952 2,614,976 Patnode Oct. 21, 1952FOREIGN PATENTS 713,093 Germany Oct. 9, 1941 OTHER REFERENCES PrimaryBatteries, by Cooper, second impression (1920), pages 235, 236.

Modern Plastics, October 1945, pages 149, and 218.

Ion Exchange, by Nachod (1949), pages 48-50, 62 64 and 67.

Transactions of The Faraday Society, vol. 33 (1937), pages 1073-1081.

Helvetica Chimica Acta, vol. 23 (1940), pages 795-800.

